20.10.3. Configuring Duplicate ID Cache

The server maintains caches of received values of the org.hornetq.core.message.impl.HDR_DUPLICATE_DETECTION_ID property sent to each address. Each address maintains its own address cache.
The cache is fixed in terms of size. The maximum size of cache is configured using the parameter id-cache-size in server configuration files (standalone.xml and domain.xml). The default value of this parameter is 2000 elements. If the cache has a maximum size of n elements, then the (n + 1)th ID stored will overwrite the 0th element in the cache.
The caches can also be configured to persist to disk or not. This can be configured using the parameter persist-id-cache in server configuration files (standalone.xml and domain.xml). If this value is set "true" then each ID will be persisted to permanent storage as they are received. The default value for this parameter is true.


Set the size of the duplicate ID cache to a large size in order to ensure that resending of messages does not overwrite the previously sent messages stored in the cache.